So, I had three thermometers reading three different temps, ranging from 102 degrees to 95. So, I put the oven on 200, let it preheat, and stuck them all in the oven together in a pan on a blanket. My expensive ones continued to say low numbers. My only accurate thermometer was the (non-digital) one that came with my hovabator! Go figure! Anyone else use this method to figure out which thermometers are being accurate?